Manually operable trip-free circuit breaker



Oct. 1, 1957 E. A. BERTHIER 2,808,486

Irma liar.-

1 KLGJWQ ATTIYS' United States Patent Ofiflce 2,808,486 Patented Oct. 1,1957 MANUALLY OPERABLE TRIP-FREE CIRCUIT BREAKER Emile Andr Berthier,Villefranche-sur-Saone, France Application February 12, 1954, Serial No.409,969

Claims priority, application France February 16, 1953 8 Claims. (Cl.200-116) My invention has for its object an electric circuit breaker orcut-out of the general type disclosed in my prior U. S. Patent No.2,467,653 issued on April 19, 1949.

The circuit breaker of the present invention includes, in

addition to tripping mechanism which responds to electrical overloads, acompact manually operable reset mechanism of the trip-free type togetherwith manually operable tripping mechanism.

A feature of the circuit breaker of the present invention resides in thecompactness of the manual control portion of the circuit breaker whichpermits the breaker to be produced in a materially smaller size for thesame rating as compared with circuit breakers of conventionalconstruction.

Another feature of the invention involves the provision of a compactcontrol unit which embodies both a manually operable tripping portionand a manually operable reset portion. In one embodiment of theinvention a single push button extension of the tripping member servesto reset the breaker. With the breaker closed, increased pressureapplied to the push button serves to trip the breaker manually.

Generally, the circuit breaker comprises an enclosing cover and a basemember both formed of insulating material. Advantageously, the basemember may be provided with terminals of the plug-in type. A fixed orrelatively stationary contact member is carried by the base member.There is a movable contact member which is engageable with the fixedcontact member, the movable contact member being carried at the free endportion of a movable contact arm. The movable contact member is movabletoward and away from the fixed contact member, the movable contact armbeing connected with the base member. The circuit to be controlled andprotected against overload by the circuit breaker extends through thefixed and movable contact members which are serially included therein.Spring means or the like resiliently urge the movable contact memberaway from the fixed contact member.

A longitudinally inwardly movable control unit extends transversely ofthe movable contact arm in close proximity thereto. The control unit ispressed outwardly by a spring. The control unit comprises a control rodwhich is longitudinally slotted and which carries an elongated latchmember disposed in the slot, the latch member being pivotally connectedintermediate its ends to the control rod. The latch member has a notchformed therein inwardly of its pivotal connection to the control rod andthis notch is selectively engageable with the movable contact arm forresetting the breaker and holding it closed, the breaker being trippedin all cases by disengagement between the contact arm and the notch.

The control unit also comprises a manually operable outwardly springpressed tripping member which is longitudinally slidable with respect tothe control rod. The tripping member has an outwardly extendingprojection which terminates in a button for manually tripping thebreaker, the tripping member being provided with a sloping cam surfacewhich cooperates with an outer free end portion of the latch member fordisengaging the notch from the contact arm to trip the breaker by inwardpressure exerted on the tripping button. The tripping button ispositioned adjacent to the outer end of the control rod. in oneembodiment of the invention, the breaker is reset by inward pressureexerted on the outer end of the control rod independently and withoutpressing on the tripping button. Thus, the breaker may be manually resetor tripped at will by inward pressure exerted either on the outer end ofthe control rod or on the tripping button, respectively.

A further latch engages the control rod for holding the contacts closedand this further latch is tripped by the contact arm to free the controlrod and allow it to move outwardly under the influence of its springafter the contact arm has first been released from the notch in thelatch member. This provides the trip-free action in cooperation with thelatch member which releases the contact arm.

In another embodiment of the invention the tripping button is actuatedwith reduced pressure to reset the breaker and an increased pressure isapplied to the tripping button for manually tripping the breaker.Springs of different characteristics are provided for this purpose. Bythe use of a single button both for tripping and resetting the breaker,the compactness of the breaker may be greatly increased.

Various additional objects, features and advantages of the inventionwill become apparent upon reading the following specification togetherwith the accompanying drawing forming a part hereof:

Referring to the drawing:

Fig. 1 is an incomplete or partial perspective view of my prior cut-outfrom which the cover has been removed.

Figs. 2 and 3 are longitudinal sectional views of the same breaker towhich the improvements according to my invention have been applied, Fig.2 showing it in its closed position and Fig. 3 showing it when trippedor released.

Figs. 4 and 5 are horizontal sectional views, respectively through lines44 and 5-5 of Fig. 2.

Fig. 6 is a front elevational view of the manually operable innerreleasing or tripping push member shown alone.

Referring to Fig. 1, there is shown diagrammatically the circuit breakerof my prior Patent No. 2,467,653, referred to above. It includes amovable contact 2 carried by a flexible blade 3 which is held in its setcontactmaking position by engagement of a latch blade 4 carried by apush rod 5; this flexible blade 3 is acted upon by a spring 6 which mayform part of it and the push rod 5 is held in its inward positioncorresponding to the closing of the movable contact 2 over thestationary contact 7 by a spring-urged pawl 8. The release correspondingto the separation of the contacts 2 and 7 is produced by the deformationof a bimetallic strip 9, which presses the latch blade to make it recedeinto its housing in the pushrod 5, so releasing the flexible blade 3which, being suddenly retracted, strikes the tail end of the pawl 8thereby releasing the push rod which a further spring 10 urges into itsouter released position, the latch blade 4 at the same time reengagingthe released flexible blade 3 carrying the movable contact 2.

By reason of the desirability of providing a positively controlledmanual release from the outside of the casing of the breaker it ispossible, as disclosed in my prior patent, to provide in an advantageousmanner the said casing with an auxiliary push member, which is notillustrated in Fig. 1, said auxiliary push member when depressed throughthe opening at 1 acting through the agency of a rocking lever, which isnot illustrated, on the pawl 8 which holds the push rod in its inwardoperative position; this operation of the auxiliary push member producesthe release of the movable contact, which is no longer held in itsoperative position by the now released push rod. This arrangement hasprovided extremely satisfactory results. The mounting of the releasingpush button leads, however, in addition, to a greater intricacy ofstructure, to a somewhat objectionable increase in size.

In order to remove these drawbacks, I have devised an improved cut outof the type referred to hereinabove, but with the difference that thereleasing push member is inwardly coaxial with the upper hollow end ofthe resetting push rod and is adapted to produce the desired releasethrough a pivotal shifting of the latch blade or lever, which forms theretaining member for the flexible blade carrying the movable contact orcontacts, said pivotal movement of the latch member being produced bythe shifting of the end of an arm, forming an extension of said latchmember inside the resetting push rod, over a slope formed on the innerend of the releasing push member.

This inner releasing push member is slidingly housed inside a recess ofthe resetting push rod and is submitted therein to the action of aspring which urges it outwardly, said spring being either: more powerfulthan the spring 10 urging the resetting push rod into its releasedposition so as to allow resetting by depressing indifferently either ofthe two knobs controlling the coaxial push member and rod, or else lesspowerful than said spring 10 urging the resetting push rod into itsreleased position, which condition requires resetting by actingexclusively on the knob on the outer resetting push rod.

Furthermore, and according to another feature of my improved cut out,the speed of release is considerably increased, which is important inthe case of large excess currents by shifting the rocking latch memberwhich locks the push rod through the agency of a movable armaturecarried by the plunger core of an electromagnetic coil positioned on thebase of the cut out and permanently fed by the electric current flowingthrough the circuit controlled by said cut out.

In all the figures, 5 designates again the resetting push rod associatedwith the latch blade or lever 4. In the embodiment illustrated of myimproved cut-out, the resetting push rod 5 is longitudinally slotted at12 for housing the latch lever 4 which is provided with a notch 13 forholding in position the flexible blade 3 carrying the movable contact,which is not shown in Figs. 2 to 6. Said latch lever 4-, which ispivotally secured to a pivot 14 extending across the longitudinal slot12, includes beyond said pivot an arm 15 the free end of which forms atail piece 16, the part played by which will be disclosed hereinafter.

The upper hollow end of the pusher rod 5 forms an axially recessedsection or push button 17 controlling the resetting of the cut-out.Inside the cylindrical recess 18 formed in the hollow push button 17 isslidably mounted an auxiliary push button 19 adapted to produce thepositive release of the cut-out.

The inner push-button 19 is also provided with an axial recess 21 whichopens into the lower end of said button while a coil spring 22 is heldbetween the movable bottom of said recess 21 and the stationary bottomof the recess 18 in the outer push button 17, the two recesses facingeach other. It is thus apparent that the spring 22 raises the inner pushmember 19 with reference to the outer push member 17, the movements ofthe push member 19 with reference to the push member 17 being howeverlimited by a stay or the like stop 23 rigid with the outer push member17, which stay extends through a vertically elongated slot 24 cut acrossthe upper part of the inner auxiliary push member 19.

The arrangement and size of these diiferent members are selected in amanner such that the upper surface 19a of the push member 19 is flushwith that of the outer push member 17 when inoperative and that thereexists, between the lower surface of the inner push member 19 in itsinoperative position and the bottom of the housing 13 in the outer pushmember 17, a spacing corresponding to the shifting of the inner pushmember required for releasing the cut-out. At its upper end, the innerpush member 19 is furthermore provided with an upwardly projectingsection 19]) the height of which is equal to last mentioned spacing.

To produce the release of the cut-out, there is provided, inside theinner push member 19 and in register with the slot 12 in the push rod 5,a recessed area 25, the surface of which facing the slot 12 assumes aslope as shown at 26. This sloping surface is engaged by the tail-piece16 on the arm 15 forming an extension of the latch member Obviously,when the cut-out is in its set position, the yielding blade 3 carryingthe movable contact is held in position as illustrated in Fig. 2 by thestop formed by the notch 13 in the latch lever 4. Obviously also, therelease of the cut-out is normally obtained as a result of the expansionof the bi-metallic strip 9, which latter when fed by an excess currentof predetermined intensity is deformed and engages the lower end of thelatch member 4 so as to make the latter rock round the pivot 14 andrelease the flexible blade 3 which consequently urges the movablecontact away from the stationary contact.

In order to obtain manually and positively the same release, it issufficient, according to my present invention, to depress the projectingsection 1912 of the inner push member 19. As a matter of fact, thedepression of said push member 19 in the direction of the arrow 27 ofFig. 2 produces, through action of the slope 26 on the tail-piece 16 ofthe lever 154, an angular movement of the latter round the pivot 14, asillustrated by the arrow 28 in Fig. 2. As precedingly, the lower end ofthe lever 4 returns inside the housing 12 formed in the push rod 5 andthe yielding blade 3 carrying the movable contact is again released andthe push-rod 5 is sped upwardly as in the case illustrated in Fig. 1.The position thus reached is illustrated in Fig. 3.

For resetting the cut-out, it is sufficient to depress simultaneouslythe two push members 17 and 19, the latter being acted upon through itslower section 19a. This operation of the cut-out has been described withthe assumption that the spring 22, acting on the inner push member 19,is less powerful than the spring 10, not illustrated in Figs. 2 to 6,urging upwardly the system including the push rod 5 and the push members17 and 19. The operation in the case of a more powerful spring has beenreferred to hereinabove.

The release of the cut-out may be furthermore obtained automatically andin a practically instantaneous manner in the case of large excesscurrents by resorting to the electromagnetic coil 29 carried by the baseof the cut-out (Fig. 5) underneath the push rod 5 and the latch lever 4.The plunger core 31 inside said electromagnetic coil includes as amatter of fact a head 32 engaging one of the arms of a right angledlever 33, the apex of which is rockably mounted on a stationary pivot 34while its second arm faces the edges of the lower section of the latchlever 4. It is apparent that, if the coil 29 is fed with a suflicientexcess current, it attracts the plunger core 31, which in its turnproduces the pivotal movement of the lever 33 in the direction of thearrow 35 of Fig. 5 round the pivot 34. Consequently, the free arm of thelever 33 shifts the latch lever 4 which rocks round the pivot 14 andproduces in the manner already disclosed the release of the cut-out.

Obviously, my invention should not be construed as defined by thelimitations of the above disclosure and it covers in fact all themodifications thereof falling within the scope of accompanying claims.

What I claim is:

1. A circuit breaker of the class described, comprising: a base member;a fixed contact member carried by said base member; a contact armconnected with said 'base member and having a free end portion thereofmovable toward and away from said fixed contact member; a movablecontact member carried by said free end portion and engageable with saidfixed contact member; an electrical circuit extending through saidcircuit breaker and controlled thereby, said fixed and movable contactmembers being serially included in said circuit; means resilientlyurging said movable contact member away from said fixed contact member;a longitudinally movable control rod extending transversely of saidcontact arm in proximity thereto, said control rod having an outer endportion which is engageable for manually resetting said breaker; anelongated latch member carried by said control rod and pivotallyconnected thereto intermediate its ends, said latch member having anotch formed therein inwardly of said pivotal connection for selectiveengagement with said contact arm; a manually operable tripping membercarried by said control rod longitudinally slid-ably with respectthereto, said tripping member having an outward extension which providesa manually operable tripping button disposed adjacent to the outer endportion of said control rod, said tripping member comprising a camsurface cooperating with an outer free end portion of said latch memberfor disengaging said notch from said contact arm in response to inwardmovement of said tripping member; a first spring means urging saidtripping member outwardly with respect to said control rod; a secondspring means urging said control rod outwardly with respect to said basemember; further latch means for holding said control rod in its inwardposition to maintain said contact members in engagement duringengagement of said notch with said contact arm, said further latch meansbeing actuated to release said control rod by engagement with said freeend portion of said contact arm upon movement thereof away from saidfixed contact member; and electrically actuable tripping means seriallyincluded in said circuit, said electrically actuable tripping meanscomprising a movable portion which cooperates with an inner free endportion of said latch member to disengage said notch from said contactarm whenever the current in said circuit exceeds a predetermined maximumvalue.

2. A circuit breaker according to claim 1, in which said control rod hasa longitudinal slot formed therein, said latch member being disposed insaid slot.

3. A circuit breaker according to claim 1, in which said tripping buttonand said outer end portion of said control rod are of circularcross-sectional and said tripping button is concentrically disposedwithin said control rod outer end portion.

4. A circuit breaker according to claim 1, wherein said first springmeans is weaker than said second spring means and wherein said controlrod outer end portion is manually engageable independently of saidtripping button.

5. A circuit breaker according to claim 1, wherein said first springmeans is stronger than said second spring means, said circuit breakerbeing resettable by pressing on said tripping button with a pressuresufiicient to overcome the action of said second spring means yetinsufficient to overcome the action of said first spring means, and saidcircuit breaker being manually trippable by pressing on said trippingbutton with pressure sufficient to overcome simultaneously the action ofboth of said first and second spring means.

6. A circuit breaker according to claim 1, wherein said electricallyactuable means comprises a bimetallic thermally responsive member heatedby current flow in said circuit.

7. A circuit breaker according to claim 1, wherein said electricallyactuat-able means comprises an electromagnetic device having anoperating winding connected in said circuit.

8. A circuit breaker of the class described, comprising: two cooperatingcontacts; a first spring means resiliently urging one of said contactsaway from the other; movable contact arm means connected with one ofsaid contacts for maintaining said contacts in engagement and permittingsaid first spring means to cause disengagement therebetween; a controlunit transversely movable with respect to said contact arm, said controlunit comprising a control rod member; a second spring means urging saidcontrol rod in the contact disengaging direction of movement of saidcontact arm; a latch member carried by said control rod and having a.notch formed therein for selective engagement with said contact arm,said latch member being pivotally connected intermediate its ends tosaid control rod member; a manually engageable outwardly spring pressedtripping member included in said control unit and movable with respectthereto to engage said latch member for causing contact arm disengagingmovement of said notch; said circuit breaker further comprising furtherlatch means for holding said control unit to maintain said contactsengaged with said contact arm engaged in said notch, said further latchmeans being tripped to release said control unit by contact disengagingmovement of said control arm; an electrical circuit extending throughsaid contacts for control thereby, and electrically actuable trippingmeans serially included in said circuit, said electrically actuabletripping means comprising a movable portion which cooperates with saidlatch member to disengage said notch from said contact arm whenever thecurrent in said circuit exceeds a predetermined maximum value.

References Cited in the file of this patent UNITED STATES PATENTS1,990,122 Hauser Feb. 5, 1935 2,043,470 Dyer et a1. June 9, 19362,127,319 Zahradnik Aug. 16, 1938 2,156,761 Jackson et a1 May 2, 19392,335,082 Platz Nov. 23, 1943 2,467,653 Berthier Apr. 19, 1949 2,519,297Stump et a1 Aug. 15, 1950

